This invention deals with a new and novel dynamic exercising device intended to improve the performance of age or disease impaired human respiratory systems.
The human respiratory system must continuously deliver a fresh oxygen supply to all of the body's tissues and organs to maintain human life. Concurrently all of the by-produced exhaust gases produced by oxidative metabolism of fuel molecules in tissue cells must be removed from the body. Efficient functioning of the "almost foolfroof" respiratory system maintains constant delivery of fresh air into the tiny lung alveoli. Exhaust gases are returned via circulating blood to the alveoli cavities and removed by exhalation. Human respiration is a well engineered, complex physio-chemical process. When specific muscles contract, work is done to lift the weight of the chest and increase the cavity volume, resulting in negative pressure inside the thoracic cavity which causes lung volume to increase. Additional air at atmospheric pressure is then sucked into the newly expanded spaces until internal and external pressures are balanced. As long as air pressure in the tiny alveoli at the ends of the bronchioles remains subatmospheric and there are no obstructions, air will continue to fill them. It is important to remember that the amount of the air that can be inhaled will be related to the fraction of the vital air capacity that has been exhaled prior to inhalation. Additional new air will not enter a cavity already containing air at the same pressure. Air flow through very small diameter tubules is not instantaneous. Flow resistance increases with tube length and decreases with interior diameter of tubes. Pressure differences are critically important to the kinetics of gas movement into lung openings.
During air exhalation the chest wall and diaphragm relax and the chest cavity volume decreases. Exhalation is a passive process during normal breathing. To exhale, all the body must do is relax. Exhalation occurs when the respiratory muscles relax and the chest springs back to its unexpanded, unstretched shape. The diaphragm rises upward into its uncontracted position. The ribs move inward, and the sternum moves to a lower position. The chest cavity, enlarged a few moments earlier, returns to it's smaller size. As the chest cavity becomes smaller, its walls exert pressure on the lungs, forcing them to occupy a smaller space. As the lungs are pressed inward, and as their own stretchiness, or elasticity, helps them to return back to their unexpanded shape, air is forced out from the alveoli through the bronchi, past the larynx, into the nasopharynx, and out the nose or mouth. It is important to note that exhalation does not empty the lungs entirely. If it did, the alveoli would collapse, greatly increasing the work required for the body to inhale the next breath.
Another reason why the lungs do not completely deflate is that blood is always circulating through them, picking up oxygen and releasing carbon dioxide. If the lungs were empty part of the time, they would contain no oxygen for the blood to pick up, and the journey of the blood would be wasted during that empty time. In fact, even if a person breathes out as much air as possible, about one-fifth of the lung's air capacity still remains filled. This volume called the "residual volume" cannot be exhaled no matter how hard a person tries. Therefore, the blood's journey through the lungs is always a useful one.
Blowing up balloons, forcing air expiration through pursed lips, and blowing a piece of paper or ping pong balls across the floor are the common recommended procedures for exercising the lungs because the activities require more air velocity than produced by passive exhalation. It seems probable that higher interpulmonary pressure causing higher exchaust gas velocity must be due to involvement of additional breathing muscles, such as abdominal muscles, rather than the simple relaxation of the respiratory muscles. It should therefore be possible to improve the conditioning of these muscles by special exercise regimes, that is, having a person exhale repeatedly against a specific resistance, to provide greater compression of lung alveoli then can occur during normal breathing to help remove additional exhaust gases, and in turn, assist in inhaling larger volumes of fresh air.
Thus, the inventors herein, one personally faced with the problem of low air capacity and reduced ability to exhale exhaust gases, and the other understanding the requirements for building up the vital capacity, collaborated to invent, design and build the devices disclosed herein.
The devices of the instant invention are of the piston and tube type and are new and novel and allow for the convenient exercise of the lungs to increase vital lung capacity and aid in the recovery of patients suffering from lung incapacity due to age or illness. Also included within the scope of this invention is the novel piston which is used in the lung exercisers.